Rotary swager



Sept. 20, 1966 K. w. HALLDEN ROTARY SWAGER Filed March 4, 1964 5 Sheets-Sheet l INVENToR Afa/"Z h/Hsz//de/v Sept. 20, 1966 K. w. HALLDEN 3,273,367

ROTARY swAGER Filed March 4, 1964 5 Sheets-Sheet 2 Sept- 20, 1966 K. w. HALLDEN 3,273,367

ROTARY SWAGER Filed March 4, 1964 3 Sheets-Sheet :5

United States Patent O 3,273,367 ROTARY SWAGER Karl W. Hallden, Thomaston, Conn., assignor to The Hallden Machine Company, Thomaston, Conn., a corporation of Connecticut Filed Mar. 4, 1964, Ser. No. 349,283 20 Claims. (Cl. '72-76) This invention relates to metal swaging in general, and to swaging apparatus and a swaging method in particular.

The present invention is concerned with the swaging of metal stock by rotary dies in so-called rotary swagers which customarily have a power-driven spindle with a head in which one or more pairs of companion dies are guided for radial movement to and from stock therebetween, and a roller unit having a plurality of rollers in a ring-like cage which are backed against an outer race and impart short inward blows to the passing dies customarily through intermediation of die-backing hammer blocks. While these rotary swagers perform generally satisfactory, they leave much to be desired in a few, but important, respects. Thus, friction between the rollers and die-backing hammer blocks in particular is quite high owing to the forceful and exceedingly rapidly repeating gliding impacts between them at necessarily high spindle speed relative to virtual standstill of the roller unit despite its usual freedom to turn and respond in characteristic orbital motion to the spindle drive. This high friction not only brings about early and excessive wear of the parts involved, but even more important, impairs the very efficiency and accuracy of swaging operations. Thus, while early and excessive wear alone of the parts ensuing from high operational friction soon lowers the initial swaging efficiency and accuracy of rotary swagers, this high operational friction affects the performance of rotary swagers even more basically in that it hampers the attainment of the very element which makes for the ultimate in efficiency and accuracy of a swaging operation, namely high kinetic energy of the dies at their blows against the stock for most direct and abrupt, as well as locally closely confined, ow bursts of the metal of the stock which afford the dies optimum control over the metal flow in even the most extensive swaging operations and result in finishswaging of stock with the least die blows. Instead, the greatly curtailed energy of the dies at their blows against the stock in rotary swagers, ensuing from the high operational friction between the vital operating parts of the latter involves exceedingly restricted flow response of the metal to the die blows. As a result, the performance rate of rotary swagers is in any event quite low and rapidly becomes intolerably low for swaging operations involving more extensive reworking of cross-sectional stock shapes into different ones, and equally important, swaging operations involving more intricate reforming of stock or reforming stock of the harder metals, or both, require increasing and even exceptional skill and intimate knowhow in setting up and also maintaining the operation, owing to characteristic, relatively sluggish flow response of the metal to the die blows which may readily set up in the metal stresses of prohibitively high and even destructive magnitude. Furthermore, the likelihood of setting up prohibitive, yet unnoticed, stresses in the metal on subjecting stock of more extensive reformation or of the harder metals, or both, to rotary swagers may well leave in doubt the adequacy of the finished stock in the important respect of its structural strength.

It is the primary aim and object of the present invention to provide for rotary stock swaging which largely overcomes the aforementioned shortcomings of prior rotary stock swaging, yet involves equipment which in structural simplicity and cost is comparable to ordinary rotary swagers.

It is another object of the present invention to provide such equipment in the form of a rotary swager of a type which has in common with conventional rota-ry swagers the principle of deriving the swaging blows against stock through cooperation between relatively turnable die and surrounding roller units, but differs from the structure and operation of conventional rotary swagers in the vital respect of having no operational friction between the operating parts and especially between the dies and rollers, thereby substantially eliminating the primary cause of the aforementioned shortcomings of prior rotary stock swagmg.

It is a further object of the present invention to devise a method of rotary stock swaging according to which friction is eliminated in and for the generation of swaging blows of `optimum energy against the stock, by simultaneously driving the die unit about its axis and the surrounding rollers about their respective axes at speeds and in directions such that the die-backing hammer blocks and rollers have on impact substantially synchronous speed in the same direction at their impacting surfaces.

Another object of the present invention is to provide a rotary swager of this type which for its performance in accordance with the aforementioned method preferably has in its roller unit an even number of at least two outer and inner roller sets arranged in a cage in angularly spaced groups of contacting and preferably radially aligned outer and inner rollers, of which the outer rollers rest on a fixed -outer race, with the cage and rollers therein, as well as the die assembly, being simultaneously driven at speeds and in directions such that the outer rollers ride substantially without slippage on the fixed race and the inner rollers ride substantially without slippage on the outer rollers and have on their impacts with the die-backing hammer blocks substantially synchronous speed in the same direction with the latter, which requires that the die and roller units are driven in opposite directions. With ythis preferred arrangement, the combined speed of the die and roller units may be very high for an exceedingly large number of die blows per time unit against the stock and a correspondingly high performance rate of the swager, yet the drive of the die unit may be kept at a rate at which centrifugal force of the dies does not appreciably impede their high-energy blows against the stock.

A further object of the present invention is to provide a rotary swager of this type in which the die and roller units are driven in opposite directions as aforementioned, and the inner and outer rollers are driven solely by virtue of their drag on each other and on the fixed outer race, respectively, stemming from their pressure contact with each other and with the race 'by centrifugal force of a magnitude adequate for the purpose.

Another object of the present invention is to provide an alternative rotary swager of this type in which the die and roller units are driven in opposite directions as aforementioned, but the contacting outer and inner rollers are driven by coaxial meshing gears of which those of preferably the outer rollers are in mesh with a fixed ring gear.

Further objects and advantages will appear to those skilled in the art from the following, considered in conjunction with the accompanying drawings.

In the accompanying drawings, in which certain modes of carrying out the present invention are shown for illustrative purposes:

IFIG. l is `a plan View of a rotary swager embodying the present invention;

FIG. 2 is a fragmentary section through the same swager taken `substantially on the line 2-2 of iFIG. 1;

FIG. .3 is another fragmentary section through the same swager taken substantially on the line 3-3 of FIG. 2;

`FIG. `4 is a fragmentary transverse section through a swager embodying Ithe present invention in a modified manner;

FIG. 5 is a fragmentary iongitudinal section through a swager embodying the present invention in another modified manner;

FIG. `6 is a section taken on the line K6 6 of FIG. 5;

FIG. 7 is a fragmentary longitudinal section through a swager embodying the present invention in a further modified manner; .and

FIG. 8 lis a section taken on the line 18-8 of FIG. 7.

lReferring to the drawings, and more particularly to FIGS. 1 to 3 thereof, the reference numeral 10 designates a lrotary swager having as its major operating corn- -ponents a die unit 12, `a yroller unit "14, `and `a power drive 16. The die tand roller units 12 and `14 are mounted in upright Ifront and rear brackets 118 and 20 on a base 22, while the power drive 16 is mounted on the base 22.

The die unit 12 comprises a plurality of swaging dies .24 in `machined ways 26 in the head 28 of a spindle 30 `which ris turnable about -an taxis x (FIGS. 1 and 2). The dies 24, which are movable in their respective ways 26 inwardly `and outwardly, and in this instance radially with respect to the axis x, are arranged in two exempl-ary pairs of which those of each pair are diametrically opposite each other. Backing the dies `24 in conventional manner Iare hammer blocks 132 and suitable shims 34, with the dies, hammer blocks and shims ybeing retained in the respective ways 26 by a face plate 36 which at 38 is bolted to the spindle head 28. The spindle 30 is in this instance journalled in antifriction lbearings 40 and 42 in a hollow spindle 44 which, in turn, is journaliled in antifriction 'bearings 46 and 48 in the front and rear Abrackets l18 and 20.

The roller unit 14, which surrounds the die unit 12, comprises a plurality of rollers L50 in `a cage formation -52 in the enlarged head `54tof the hollow spindle 44. In accordance with one `aspect of the present invention, the rollers 50 are arrange-d in the cage 52 in an even number, in this instance two, rows 52 and `54 of different radial spacing from the -axis x `and concentric with respect to this axis, of which the rollers of -both rows are further `arranged in roller groups 56 -which `are spaced apart, in this instance equiangularly, about the axis x, with each roller group I5.6 having inner and outer rollers 50a and 50h which are in rolling contact with each other, and -in this instance .are also radially aligned with each other. tFurther, the outer rollers of each group S6 are in rolling contact with a fixed outer race 58 in the front bracket 18. Moreover, all rollers 50 are in this instance of the same diameter. For the formation of the .cage 52 in the spindle head 54, the latter is provided with `a plurality of axial bores 60 in which the rollers 50 are received with slight peripheral play to permit independent operational rotation of the same therein. The rollers A5t) are retained in the cage 52 by a ring 62 which at '164 is ybolted to the spindle head 54.

In accordance with another aspect of the present iuvention, the die unit 12 as well as the roller unit 14 are driven in opposite directions for operation of the swager. For the drive of these units, the power drive 16 comprises a prime mover in the exemplary form of an electric motor S66 (FIG. 1) which through a coupling 68 is connected with fa shaft 70 that is journalled in suitable bearing brackets 72 and 74 on the base 16 and carries a gear 76 and 4a sprocket 7'8. The gear 76 is in mesh with a gear 80 which at 182 is keyed to the outer spindle 44 (lFIG. 2), while the sprocket '78 is through a chain 84 connected ywith a sprocket 86 which at 8'3 is keyed to the inner spindle 30. Accordingly, the die and roller units 12 and 114 are driven in opposite directions on the power drive of the counter shaft '70 in one direction.

The swager is 'also provided with a front cover 90 which at 92 is bolted to the front bracket 18 and carries a central guide 94 through which to pass stock to-beswaged, such as tubing, for anstance, between the dies 24. For further passage of stock through the swager, the inner spindle Sii and also a cover plate 96 on the sprocket 86 are centrally apertured at 93 and l101), respectively.

In operation of the swager, i.e., on the described power drive of the die and -roller units 12 and 14 in opposite directions, the die-'backing hammer blocks 32 are at their outer surfaces 102'impacted by the peripheral surfaces of the passing inner rollers 50a, with the result that the hammer blocks 32 and associated dies 50 rebound inwardly to impart swaging blows to stock therebetween, with the hammer 'blocks and associated dies being intermittently thrown outwardly lby centrifugal `force between successive roller impacts, as will be readily understood. For simplicity of description, the dies and their respective hammer blocks are in the following description and appended claims referred to simply as dies The operation of the present invention is according to `a method which yforms another important aspect of the present invention, and which involves simultaneously driving the die unit and the rollers in directions and at relative speeds such that the yrollers ride substantially without slippage on each other and on the fixed outer race, and the dies and rollers have on impact substantially synchronous speed in the same direction at their impacting surfaces. To this end, the roller unit 14 is driven at a speed which is sufficiently high to compel the rollers into centrifugally induced pressure contact with each other and the fixed outer race at which they will respond to the roller uni-t drive in substantially slipfree ride on each other and on the race, while the die unit 12 is driven at ya speed `at which the dies ,and rolle-rs have on impact the required substantially synchronous speed in the same direction at their impacting surfaces. The rollers '50 will thus respond in their rotation to the `drive of the roller unit as though the fixed outer race 58 were a ring gear yand the rollers of each group had meshing peripheral tee-th of which those of all outer rollers *50h were also in mesh with the ring gear. Thus, assuming the rollers and outer race to be geared together as just mentioned, and the power drive of the roller unit 14 to be counterclockwise as indicated "by the arrow 104 in FIG. 3, i-t stands to reason that the outer rollers 501; will without slippage roll clockwise on the iixed race Sit-and `the inner rollers 50a will without slippage roll counterclockwise on the associated outer rollers 50h, with the exemplary drive lof the die unit y12 being clockwise as indicated by the arrow 106 in FIG. 3. This, coupled with Ithe opposed drives of the die and roller units 12 and 14 at appropriate relative speeds will bring about the required substantially synchronous speed of the rollers and dies on their impact at their impacting surfaces.

As a result of the featured operation of the swager, the same is virtually devoid of operational friction in its swagering-blow generating structure, Wherefore the swager will be subject to hardly any wear and perform efficiently and accurately for the longest time, with the swager being, moreover, comparable to conventional rotary swagers in its structural simplicity `and cost. However, the virtual absence of operational friction in the generation of the swaging blows is even far more important in `attaining the ultimate in efficiency and accuracy of a swaging operation `and also quality of the swaged product. Thus, virtual absence of operational friction in the swaging-blow generating structure makes for impact between the dies and the rollers to which the dies respond with inward rebound of optimum kinetic energy which on the blows of the dies against the stock causes most direct and abrupt, as well as locally closely confined, ow bursts of the metal of lthe stock which afford the dies optimum con-trol over the metal ow in even the Imost extensive swaging operations `and result in finish-swaging of stock with the least die tblows and the least work-hardening. Also, the highenergy die blows against the stock and ensuing flow response just vdescribed of the metal of the stock results in swaged products of optimum quality in point of structural strength and accuracy in shape `and size, in that the metal flow is most direct and least tortuous and, hence, meets with the least resistance, which is highly conductive to keeping internal stresses in the metal at a negligible level and distributing the metal most uniformly over the blow path of the rotating dies. Further, the high-energy die blows against stock and ensuing ready flow response of the metal of the stock, while advantageous in the simplest swaging operations, is even more advantageous in more complex swaging operations, such as more extensive reworking of cross-sectional stock Ishapes into different ones, or reforming of stock of the harder metals, or both, because such operations become entirely predictable in their outcome and may easily be set up and maintained without requiring either exceptional skill and know-how or close supervision, or both. Moreover, the high-energy die blows against stock `and ensuing ready flow response of the metal of the stock readily lend themselves to extensive reworking of stock which heretofore was unattainable or impractical lwith conventional rotary swagers. Another great advantage of the present swager is its exceedingly high production rate. Thus, by driving both, the die and roller units, and eliminating the free orbital motion of the roller unit in most conventional swagers, the number of die blows per time unit in the present swager is already over twice the number of die blows in a conventional swager `at the same speed of the respective die units. Furthermore, owing to the virtually frictionless performance of the die-blow generating structure in the present swager, each of the die and rolle-r units may be, and is preferably, driven at considerably higher speed than the permissible maximum speed of the die units of conventional swagers within limits at which operational friction between dies and rollers is not yet defeating the swaging function of the dies. The die and roller uni-ts of the present swager are thus advantageously driven at very high combined speed `for an exceedingly large number of ldie blows per time unit, yet the drive of the die -unit may be kept at a rate at which centrifugal force of the dies does not appreciably impede their highenergy blows against the stock. The exceedingly large number of die blows against stock in the present swager, coupled with the fact that finish-swaging of the stock is achieved with a minimum of die blows, thus results in an exceedingly high production rate of the swager. Just to give an example in this respect, a swaging operation on tubular stock involving quite extensive reformation in size and especially shape of the stock was undertaken in a conventional rotary swager at a maximum permissible stock feed rate of approximately two feet per minute which could not be surpassed without ruining the operation, while exactly the same swaging operation was performed entirely satisfactorily in a swager exactly as shown and performing as described at an astonishing stock feed rate of twenty feet per minute, with the permissible maximum perform-ance rate of this swager being not even in sight as yet.

While in the described exemplary swager there are preferably two concentric rows of rollers in the roller unit, there may lobviously be more than ytwo of these roller rows as long as they are of an even number. Also, while in the described swager 10 all of the rollers of the roller unit are of the same diameter, they need not rbe. Thus, FIG. 4 shows a modified swager 10a in which the outer rollers Sb are of the same diameter and the inner rollers 50a' are also of the same diameter, but the inner rollers are of smaller diameter than the outer rollers. With this arrangement, there is between the outer and inner rollers a speed ratio other than l to l, with the inner rollers 50a being in this instance driven at greater peripheral speed than the outer rollers 50b for an optimum number of die blows per time unit,

Reference is now had to FIGS. 5 'and 6 that show another modified swager 10b which may in all respects be like the described swager 10 of FIGS. l to 3, except that the inner and outer rollers 50a and 50b of the roller unit 14h are positively driven on the power drive of the latter. To this end, the companion rollers 50a and Sflb of each group are provided with identical meshing pinions of pitch diameters equal to the diameters of the rollers, and the pinions on the outer rollers 50h" are in mesh with a fixed ring gear 112 concentric with, and of a pitch diameter equal to the inside diameter of, the fixed race 58h. The rollers 50a and 50b of each group have opposite end journals 114 and 116 of which the journals 114 support the pinions 110 in axial alignment with the respective rollers 50a and 5011 and are received with their free ends in bearing apertures 11S in the retainer ring 62b which -at 64b is bolted to the spindle head 5417, while the opposite journals 116 of the -rollers are received in bearing apertures 120 in the spindle head 54b. The pinions 110 are further drivingly connected with their respective rollers 50a and 50h by pins 122. Thus, in operation of the swager, i.c., on the power drive of the die and roller units 12b and 14b in opposite directions at appropriate relative speeds for the attainment of synchronous speed of the dies and rollers in the same direction at their impacting surfaces, the rollers 50a" and Silb are positively driven by the meshing pinions 110 and ring gear 112 for slip-free ride of these rollers on each other and on the fixed r-ace 5811.

While in the previously described swagers the roller unit has an even number of concentric roller rows, the present invention is also embodied in the swager 16C of FIGS. 7 and 8, the roller unit 14C of which has a single annular row of rollers 50c. In this swager, however, the roller unit 14C is fixed and the die unit 12C and outer race 58C, as well as the individual rollers 50c, are driven. Thus, the head 54C of the driven outer spindle 44C is by pins 126 drivingly connected with the race 58e which is turnable in an antifriction bearing 12S in the front bracket 18C. The race 58C has in this instance a ring-gear formation 130 which is in mesh with pinions 132 on the rollers 50c. The pitch diameter of the ring gear 130 is equal to the inside diameter of the race 58C, and the pitch diameter of the pinions 132 is equal to the diameter of the rollers 50c. The rollers 50c are received in a cage 134 which is separate from the spindle head 54C and held in fixed position by being bolted at 136 to a retainer ring 138 which together with the front cover 90e is bolted at 92C to the front bracket 18C. The rollers 50c carry stubs 140 which support the pinions 132 at one end and are received with their other ends in apertures 142 in the retainer ring 133, with the pinions 132 being drivingly connected with their rollers 50c by pins 144.

In operation of the present swager 10c, the die unit 12o and outer race 58C are driven in opposite directions, with the rollers 50c of the fixed roller unit 14C being, through intermediation of the ring gear 130 and pinions 132, driven from the outer race 58C in a direction opposite to that of the die unit 12e for slip-free ride of the rollers Sflc on the driven race 58C. Thus, on driving the die unit 12a` and race 58e in opposite directions at appropriate relative speeds, the dies and rollers will on impact have substantially synchronous speed in the same direction at their impacting surfaces. The present swager thus has all the advantages of the previously described swagers, except that its production rate is less owing to the fixed condition of its roller unit.

The Virtual absence of =friction in the generation of the die blows and the substantially synchronous speed in the same direction of the impacting dies and rollers at their impacting surfaces results also in less noisy operation of swagers of the present type in comparison to conventional rotary swagers. Thus, while the characteristic loud clatter of conventional swagers in operation is definitely annoying to most anyone, the noise generated by the present swagers is much less clattering and of higher pitch and has been found to be not really annoying to many.

The invention may be carried out in other specific ways than those herein set forth without departing from the spirit and essential characteristics of the invention, and the present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

What is claimed is:

1. In a rotary swager, the combination of a die unit having about a first axis inwardly and outwardly movable swaging dies with outer surfaces; a roller unit surrounding said die unit, said units being relatively turnable about said axis, and said roller unit having rollers with peripheral surfaces turnable about their own axes and spaced apart about said first axis for inward rebounding impact of said dies with said rollers at their respective outer and peripheral surfaces on relative rotation between said units; and means operative to cause simultaneous relative rotation between said units and rotation of said rollers about their own axes in directions and at relative speeds such that said rollers and dies have on impact substantially synchronous speed in the same direction at their impacting surfaces.

2. A rotary swager, comprising a die unit having about a first axis inwardly and outwardly movable swaging dies with outer surfaces; a roller unit surrounding said die unit; another unit providing a race about said axis and surrounding said roller unit, two of said units, including said die unit, being individually Iturnable about said axis relative to the remaining unit, and said roller unit having angularly spaced-apart roller parts with peripheral surfaces rotatable about their own axes and backed against Ysaid race for inward rebounding impact of said dies with said roller parts at .their respective outer and peripheral surfaces on relative rotation between said die and roller units about said first axis; and means operative simultaneously to drive said two units in opposite directions about said first axis and said roller parts about their own axes with their die-impacting surfaces in the same direction, at relative speeds such that said roller parts and dies have on impact substantially synchronous speed in the same direction at their impacting surfaces and said roller parts ride substantially slip-free on said race.

3. A rotary swager, comprising a die unit having about a first axis inwardly and outwardly movable swaging dies with outer surfaces; a roller unit surrounding said die unit; a fixed race about said axis and surrounding said roller unit, said units being individually rotatable about said axis, and said roller unit having about said axis angularly spaced groups of the same even number of rollers with 4peripheral surfaces, of which all rollers are turnable about their own axes, and the rollers of each group are in rolling contact with each other and radially differently spaced from said first axis and have outermost and innermost rollers of which the outermost roller is in rolling contact with said race, with said dies having inward rebound impact with said innermost rollers at the respective outer and peripheral surfaces thereof on relative rotation between said units; and means operative simultaneously to drive said units about said first axis and said rollers about their own axes, in directions and at relative speeds such that said units turn in opposite directions, and said innermost rollers and dies have on impact substantially synchronous speed in thesame direction at their impacting surfaces while said rollers and outermost rollers of each group ride substantially slip-free on each other and on said race, respectively.

4. A rotary swager as set forth in claim 3, in which the rollers of each group are radially aligned.

5. A rotary swager as set forth in claim 3, in which all of said rollers are of the same diameter.

6. A rotary swager as set forth in claim 3, in which the rollers of each group number two.

7. A rotary swager as set forth in claim 3, in which the rollers of each group number two and are radially aligned.

8. A rotary swager as set forth in claim 3, in which all rollers are of the same diameter, and the rollers of each group number two and are radially aligned.

9. A rotary swager as set forth in claim 3, .in which the rollers of each group are of different diameters.

10. A rotary swager, comprising a die unit having about a first axis inwardly and outwardly movable swaging dies with outer surfaces; a roller unit surrounding said die unit; a fixed race about said axis and surrounding said roller unit, said units being individually rotatable about said axis, and said roller unit having about said axis angularly spaced groups of the same even number of rollers with peripheral surfaces, of which all rollers are turnable about their own axes, and the rollers of each group are in rolling contact with each other and radially differently spaced from said first axis and have outermost and innermost rollers of which the outermost roller is in rolling contact with said race, with said dies having inward rebounding impact with said innermost rollers at the respective outer and peripheral surfaces thereof on relative rotation between said units; and a power drive operable to turn said roller unit in one direction at a speed at which centrifugal force of the rollers of each group compels them to roll on each other and the outermost roller thereof on said race substantially without slippage, and simultaneously to turn said die unit opposite to said one direction at a speed at which said dies and innermost rollers have on impact substantially synchronous speed in the same direction at their impacting surfaces.

11. A rotary swager as set forth in claim 10, in which the rollers of each group number two and all rollers are of the same diameter, and said roller unit includes a cage with apertures receiving the rollers of each group in substantial radial alignment with each other and with sufiicient peripheral clearance for their substantially slipfree drag drive.

12. A rotary swager as set forth in claim 1Q, in which said drive includes a power shaft driven opposite to in said one direction, a chain drive connection `between said shaft and die unit to drive the latter opposite to said one direction, and two meshing gears carried by said shaft and roller unit, respectively, for driving the latter in said one direction.

13. A rotary swager, comprising a die unit having about a first axis inwardly and outwardly movable swaging dies with -outer surfaces; a roller unit surrounding said die unit; a fixed race about said axis and surrounding said roller unit, said units being individually rotatable about said axis, and said roller unit having about said axis angularly spaced groups of the same even number of rollers with peripheral surfaces, of which all rollers are turnable about their own axes, and the rollers of each group are in rolling contact with each other' and radially differently spaced from said first axis and have end rollers of outermost and innermost location of which the outermost end roller is in rolling contact with said race, with said dies having inwardrebounding impact with said innermost end rollers at the respective outer and peripheral surfaces thereof on relative `rotation between said units; meshing coaxial pinions on the rollers of each group and a fixed gear -in mesh with the pinions on the end rollers of one of said locations for slip-free ride of the rollers of each group on each other and on said race on turning said roller unit relative to said gear; and a drive for turning said units in opposite directions at such relative speeds that said dies and innermost end rollers have on impact substantially synchronous speed in the same direction at their impacting surfaces.

14. A rotary swager as set forth in claim 13, in which said gear is a ring gear in mesh with the pinions on the outermost end rollers.

15. A rotary swager as set forth in claim 13, in which said roller unit includes a cage with bearing apertures, and said rollers and pinions have axial journals borne in said bearing apertures.

16. A rotary swager as set forth in claim 13, in which all of said rollers are of the same diameter and the rollers of each group number two and are radially aligned, and said pinions are identical.

17. A rotary swager, comprising a die unit turnable about a first axis and having inwardly and outwardly movabe swaging dies with outer surfaces; a fixed roller unit having about said axis a single row of angularly spaced rollers with peripheral surfaces turnable about their own axes; a race surrounding said roller unit and being turnable about said first axis and in rolling Contact with said rollers, with said dies having inward rebounding impact with said rollers at the respective outer and peripheral surfaces thereof on rotation of said die unit; coaxial pinions Ion said rollers and a coaxial ring gear on said race in mesh with said pinions for slip-free ride of said rollers on said race on rotation of the latter; and a drive for simultaneously turning said die unit and race in opposite directions at relative speeds such that said dies and rollers have on impact substantially synchronous speed in the same direction at their impacting surfaces.

18. In a method of rotary stock swaging, involving driving a die unit with inwardly and outwardly movable swaging dies in one direction relative to a surrounding roller unit with rollers for inward rebounding impact of the dies with the rollers, that improvement which comprises, holding the dies and Irollers on their impact to substantially synchronous speed in the same direction at their impacting surfaces, by driving simultaneously with the die unit drive the rollers about their own axes opposite to said one direction at appropriate speed.

19. In -a method of rotary stock swaging, involving driving a die unit with inwardly and outwardly movable swaging dies in one direction relative to `a surrounding roller unit with angularly spaced race-backed roller parts for inward rebounding impact of the dies with the roller parts, that improvement which comprises, during the dieunit drive, holding `the dies and roller parts on `impact to substantially synchronous speed in the same direction at their impacting surfaces by driving the roller parts albout their own axes at appropriate speed and with their dieimpacting surfaces opposite `to said one direction, and also relatively turning the roller unit and race for substantially slip-free ride of the driven roller parts on the race.

20. A method of rotary stock swaging lby a rotary die unit with inwardly and outwardly movable swaging dies, .and a coaxially-turnaible surrounding roller unit with angularly spaced groups of rollers, with the rollers of each group being an even number and differently radially spaced and in rolling contact with each other, and the innermost `and outermost rollers of the groups lbeing in inward-rebound impacting relation with the dies and in rolling contact with a `fixed race, respectively, which comprises driving the roller unit in one direction at a speed at which centrifugal force compels the rollers `of each group into substantially slip-free ride on each other and on the race, and simultaneously with the roller-unit drive driving the die unit opposite to said one direction at such speed that the dies and innermost rollers have on impact substantially synchronous speed in the same direction at their impacting surfaces.

References Cited by the Examiner UNITED STATES PATENTS 1,430,974 10/ 1922 Frick 72--76 1,955,535 4/1934 Conner 72-76 2,209,501 7/ 1940 Abbey 72--76 2,790,188 4/ 1957 Fray 72--402 CHARLES W. LANHAM, Primary Examiner.

G. P. CROSBY, Assistant Examiner. 

1. IN A ROTARY SWAGER, THE COMBINATION OF A DIE UNIT HAVING ABOUT A FIRST AXIS INWARDLY AND OUTWARDLY MOVABLE SWAGING DIES WITH OUTER SURFACES; A ROLLER UNIT SURROUNDING SAID DIE UNIT, SAID UNITS BEING RELATIVELY TURNABLE ABOUT SAID AXIS, AND SAID ROLLER UNIT HAVING ROLLERS WITH PERIPHERAL SURFACES TURNABLE ABOUT THEIR OWN AXES AND SPACED APART ABOUT SAID FIRST AXIS FOR INWARD REBOUNDING IMPACT OF SAID DIES WITH SAID ROLLERS AT THEIR RESPECTIVE OUTER AND PERIPHERAL SURFACES ON RELATIVE ROTATION BETWEEN SAID UNITS; AND MEANS OPERATIVE TO CAUSE SIMULTANEOUS RELATIVE ROTATION BETWEEN SAID UNITS AND ROTATION OF SAID ROLLERS ABOUT THEIR OWN AXES IN DIRECTIONS AND AT RELATIVE SPEEDS SUCH THAT SAID ROLLERS AND DIES HAVE ON IMPACT SUBSTANTIALLY SYNCHRONOUS SPEED IN THE SAME DIRECTION AT THEIR IMPACTING SURFACES. 